In the field of construction vehicles, and in particular mining trucks, it has been found that vehicle operators commonly descend hills with the transmission in neutral and the accelerator pedal completely released. However, because the transmission's cooling and lubrication systems operate at rates controlled by engine speed, insufficient cooling and lubrication can result when the vehicle is operated in the above-described manner. Additionally, excessive transmission wear can occur when the operator reengages the transmission, due to the relatively high speed differential between the transmission's planetary elements.
The subject invention is directed towards addressing the above problems by providing a controller elevating engine speed to a predetermined level when the transmission is in neutral and the vehicle speed is above a preselected value.